SYSTEM, INTERFACE DEVICES, USE OF THE INTERFACE DEVICES AND METHOD FOR EYE SURGERY

Abstract

The present invention relates to a laser system for eye surgery with an eye-surgical laser apparatus and with a set of interface devices. The invention further relates to the laser apparatus itself, to the set of interface devices itself, to the use of the set and also to a method for laser-surgical eye treatment. The laser system for eye surgery comprises the eye-surgical laser apparatus having optical components for providing pulsed focused laser radiation with radiation properties matched to the generation of photodisruptions in human eye tissue and with a control unit for positional control of the radiation focus of the laser radiation, the control unit being designed for executing various control programs that represent various types of incision figure; and a set of interface devices, each of the interface devices including a contact body that is transparent to the laser radiation, with an abutment face for abutment against an eye to be treated, and also a coupling portion for detachable coupling of the interface device onto a counter-coupling portion of the laser apparatus, the interface devices of the set differing by virtue of a differing optical effect on the laser radiation provided in the laser apparatus.

Claims

1. A laser system for eye surgery, comprising an eye-surgical laser apparatus comprising: optical components for providing pulsed focused laser radiation with radiation properties matched to the generation of photodisruptions in human eye tissue; a control unit for positional control of the radiation focus of the laser radiation, the control unit being designed for executing various control programs that represent various types of incision figures; and a counter-coupling portion; and a set of interface devices, each of the interface devices comprising: a patient adapter having a contact lens that is transparent to the laser radiation, with an abutment face for abutment against an eye to be treated; and a coupling portion for detachable coupling of the interface device onto the counter-coupling portion of the laser apparatus, different patient adapters having different lengths in the z-direction that yield different depths of focus of the laser radiation in a z-direction without changing the setting of the focusing optics, a first patient adapter having a focus location for directing laser radiation to a cornea, a second patient adapter having a focus location for directing laser radiation to a crystalline lens, a third patient adapter having a focus location for directing laser radiation to an iridocorneal angle, a fourth patient adapter having a focus location for directing laser radiation to a vitreous, and a fifth patient adapter having a focus location for directing laser radiation to a retina.

2. The laser system of claim 1, wherein at least a subset of the interface devices differ by virtue of a differing influence on the location of the radiation focus relative to the abutment face.

3. The laser system of claim 1, wherein at least a subset of the interface devices differ by virtue of a differing shape and/or location of at least one optical boundary surface.

4. The laser system of claim 1, wherein at least a subset of the interface devices differ by virtue of a differing number of optical elements.

5. The laser system of claim 1, wherein at least one of the interface devices includes an applanation cone that is designed to be coupled onto the eye and onto focusing optics of the laser apparatus.

6. The laser system of claim 1, wherein the laser apparatus further includes an adaptive optical element that is arranged upstream of focusing optics of the laser apparatus in the direction of propagation of the laser radiation.

7. The laser system of claim 6, wherein the adaptive optical element comprises an adaptive mirror or a light-transmitting adaptive system.

8. The laser system of claim 1, wherein at least one of the interface devices includes a coding/code and the laser apparatus is configured to recognise the coding/code and to call an associated control program in the control unit.

9. A set of interface devices for use in an eye-surgical laser apparatus, each of the interface devices comprising: a contact lens that is transparent to laser radiation of a laser apparatus, with an abutment face for abutment against an eye to be treated; and a coupling portion for detachable coupling of the interface device onto a counter-coupling portion of the laser apparatus, different patient adapters having different lengths in the z-direction that yield different depths of focus of the laser radiation in a z-direction without changing the setting of the focusing optics, a first patient adapter having a focus location for directing laser radiation to a cornea, a second patient adapter having a focus location for directing laser radiation to a crystalline lens, a third patient adapter having a focus location for directing laser radiation to an iridocorneal angle, a fourth patient adapter having a focus location for directing laser radiation to a vitreous, and a fifth patient adapter having a focus location for directing laser radiation to a retina.

10. The set of interface devices according to claim 9, wherein at least one of the interface devices includes a planar contact lens with a planar abutment face for abutment against the eye and the face situated opposite the abutment face is adapted to be plane-parallel to the abutment face.

11. The set of interface devices according to claim 9, wherein at least one of the interface devices includes an optical ancillary element.

12. The set of interface devices according to claim 11, wherein the optical ancillary element is arranged in the interface device in such a manner that a face facing away from the contact lens is shaped in convex or planar manner and a face facing towards the contact lens is concavely shaped.

13. The set of interface devices according to claim 12, wherein the face facing towards the contact lens and/or the face facing away from the contact lens is/are formed as a freeform surface.

14. The set of interface devices according to claim 9, wherein at least one of the interface devices includes a concavo-concave contact lens with a concave abutment face for abutment against the eye and the face situated opposite the abutment face is concavely shaped.

15. The set of interface devices according to claim 9, wherein at least one of the interface devices includes a concavo-convex or concavo-planar contact lens with a concave abutment face for abutment against the eye and the face situated opposite the abutment face is shaped in convex or planar manner.

16. The set of interface devices according to claim 14, wherein the abutment face and/or the face situated opposite the abutment face is formed as a freeform surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The invention will be elucidated further in the following on the basis of the appended drawings, which are schematic throughout. Shown are:

[0040] FIG. 1 a schematic block representation of elements of a laser device for eye-surgical treatments according to one embodiment;

[0041] FIG. 2a a schematic representation of a beam path of a laser beam for machining the cornea of a human eye;

[0042] FIG. 2b a schematic representation of a beam path of a laser beam for machining the lens of a human eye;

[0043] FIG. 2c a schematic representation of a beam path of a laser beam for machining the iris of a human eye;

[0044] FIG. 2d a schematic representation of a beam path of a laser beam for machining the iridocorneal angle of a human eye;

[0045] FIG. 2e a schematic representation of a beam path of a laser beam for machining the vitreous body of a human eye;

[0046] FIG. 2f a schematic representation of a beam path of a laser beam for machining the retina of a human eye;

[0047] FIG. 3 a further schematic representation of the beam path of the laser beam for machining the lens from FIG. 2b;

[0048] FIG. 4a a schematic representation of a first interface device for use in the laser device according to FIG. 1;

[0049] FIG. 4b a schematic representation of a second interface device for use in the laser device according to FIG. 1;

[0050] FIG. 4c a schematic representation of a third interface device for use in the laser device according to FIG. 1;

[0051] FIG. 4d a schematic representation of a fourth interface device for use in the laser device according to FIG. 1;

[0052] FIG. 4e a schematic representation of a fifth interface device for use in the laser device according to FIG. 1; and

[0053] FIG. 4f a schematic representation of a sixth interface device for use in the laser device according to FIG. 1.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0054] The laser device shown in FIG. 1—denoted generally therein by 10—comprises a laser source 12 which makes available a pulsed laser beam 14, in the case of which the pulse duration of the radiation pulses is suitable for use of the laser beam 14 for the purpose of generating incisions in the corneal tissue of an eye 16 of a patient to be treated. For example, the pulse duration of the radiation pulses of the laser beam 14 lies within the nanosecond, picosecond, femtosecond or attosecond range. The laser beam 14 made available by the laser source 12 has a pulse repetition rate such as is desired for the application in question, i.e. the repetition rate of the radiation pulses emitted from the laser device 10 and directed onto the eye 16 corresponds to the repetition rate of the radiation pulses that are available at the output of the laser source 12, unless, in a manner depending on the machining profile predetermined for the eye 16, a partial number of the radiation pulses emitted from the laser source 12 are blanked by means of an optical switch 18 arranged in the radiation path of the laser beam 14. Such blanked radiation pulses accordingly do not reach the eye 16.

[0055] In a manner not shown in any detail but known as such, the laser source 12 may include, for example, a laser oscillator (e.g. solid-state laser oscillator), a pre-amplifier, which increases the pulse power of the laser pulses emitted from the oscillator and simultaneously temporally stretches them, a subsequent pulse-picker, which selects individual laser pulses from the pre-amplified laser pulses of the oscillator, in order in this way to lower the repetition rate to a desired degree, a power amplifier, which amplifies the selected, still temporally stretched, pulses to the pulse energy needed for the application, and a pulse compressor, which temporally compresses the pulses output from the power amplifier to the pulse duration desired for the application.

[0056] The optical switch 18, which may also be designated as a pulse modulator, may, for example, take the form of an acousto-optical modulator or an electro-optical modulator. Generally, the optical switch 18 may contain arbitrary optically active elements that enable a rapid blanking of individual laser pulses. The optical switch 18 may, for example, contain a beam trap, indicated schematically at 20, which serves to absorb radiation pulses to be blanked, which are not to reach the eye 16. The optical switch 18 can deflect such radiation pulses to be blanked from the normal beam path of the radiation pulses of the laser beam 14 and direct them onto the beam trap 20.

[0057] In the beam path of the laser beam 14 further optical components are arranged which, in the exemplary case shown, include a z-scanner 22, an x-y scanner 24 and also a focusing objective 26. The focusing objective 26 serves for focusing the laser beam 14 onto a desired machining location on or in the eye 16, in particular in the cornea of the same. The z-scanner 22 serves for longitudinal control of the location of the focal point of the laser beam 14; the x-y scanner 24 serves, on the other hand, for transverse control of the location of the focal point. ‘Longitudinal’ relates in this connection to the direction of beam propagation; this is designated in conventional notation as the z-direction. ‘Transverse’, on the other hand, designates a direction transverse to the direction of propagation of the laser beam 14; according to conventional notation the transverse plane is designated as the x-y plane. A coordinate frame that represents the x-y-z directions in the region of the eye 16 has been drawn in FIG. 1 for the purpose of illustration.

[0058] For the purpose of transverse deflection of the laser beam 14, the x-y scanner 24 may, for example, include a pair of galvanometrically actuated scanner mirrors that are capable of tilting about mutually perpendicular axes. On the other hand, the z-scanner 22 may, for example, contain a longitudinally adjustable lens or a lens of variable refractive power or a deformable mirror, with which the divergence of the laser beam 14 and consequently the z-position of the beam focus can be influenced. For example, such an adjustable lens or mirror may be contained in a beam expander which is not represented in any detail and which expands the laser beam 14 emitted from the laser source 12. The beam expander may, for example, be configured as a Galilean telescope.

[0059] The focusing objective 26 is preferably an f-theta objective and is preferentially detachably coupled on its beam-exit side with a patient adapter 28a which constitutes an abutment interface for the cornea of the eye 16. For this purpose the patient adapter 28a includes a contact element 30a that is transparent to the laser radiation and that on its underside facing towards the eye includes an abutment face 32a for the cornea of the eye 16. In the exemplary case shown, the abutment face 32a is realised as a plane surface and serves for levelling the cornea, by the contact element 30a being pressed against the eye 16 with appropriate pressure or by the cornea being aspirated onto the abutment face 32a by underpressure. The contact element 30a, which in the case of plane-parallel design is ordinarily designated as the applanation plate, is fitted to the narrower end of a conically widening carrier sleeve 34a. The connection between the contact element 30a and the carrier sleeve 34a may be permanent, for example by virtue of adhesion bonding, or it may be detachable, for instance by virtue of a screw coupling. It is conceivable, furthermore, to use an optical injection-moulded part with the functions of the carrier sleeve 34a and of the contact element 30a. In a manner not represented in any detail, the carrier sleeve 34a has at its wider sleeve end, which in the drawing is the upper end, suitable coupling structures for coupling onto the focusing objective 26.

[0060] It will be understood that the order of the optical switch 18, the z-scanner 22, the x-y scanner 24 and the focusing objective 26 does not have to be as represented in FIG. 1. For example, the optical switch 18 may readily have been arranged in the beam path downstream of the z-scanner 22. To this extent, the order of these components shown in FIG. 1 is in no way to be understood as restrictive.

[0061] The laser source 12, the optical switch 18 and also the two scanners 22, 24 (which, if desired, may also have been combined within a single structural unit) are controlled by a control computer 36 which operates in accordance with a control program 40 stored in a memory 38. The control program 40 contains instructions (program code) that bring about, upon execution by the control computer 36, such a control of the location of the beam focus of the laser beam 14 that in the cornea, in the lens or at another location of the eye 16 bearing against the contact element 30a an incision figure arises that, for example in the course of a machining of the cornea, completely severs from the surrounding corneal tissue a corneal tissue volume to be removed within the scope of a corneal lenticle extraction or a corneal keratoplasty. If desired, this incision figure may additionally bring about a segmentation of this tissue volume into a plurality of volume segments individually separated from one another.

[0062] Furthermore, an adaptive optical element or adaptive optical system, taking the form, in exemplary manner, of a mirror 42, may be capable of being introduced into the radiation path of the laser beam 14 upstream of the focusing objective 26. This mirror 42 may have been designed as a deformable mirror. Furthermore, instead of the mirror 42 another adaptive optical element or a light-transmitting adaptive system may have been provided. The mirror 42 is preferentially introduced into the radiation path of the laser beam 14 if a machining of the lens of the eye 16 is to be undertaken in order to lessen (compensate) wavefront aberrations. In the course of a machining of the cornea of the eye 16 the mirror 42 may be located in a null position (inactive position) in which the radiation path that is dashed in FIG. 1 is used, without the laser beam 14 passing through the mirror 42 (without the mirror 42 influencing the laser beam 14). The control of the radiation path (e.g. whether or not the mirror 42 is introduced into the radiation path) can be implemented by the control computer 36. In an alternative embodiment the mirror remains in the beam path, so that a drive, depending on the application, is effected via an activation of the application.

[0063] In the case of the laser device 10 shown in FIG. 1 the patient adapter (interface unit) 28a is coupled in exemplary manner with the focusing objective 26. Accordingly, the eye 16 in FIG. 1 is bearing against the planar abutment face 32a of the contact element 30a pertaining to the patient adapter 28a. This patient adapter 28a is shown in more detail in FIG. 4a. Patient adapters 28b to 28e represented in FIGS. 4b to 4e form, jointly with patient adapter 28a from FIG. 4a, a set of patient adapters, all of which are preferentially capable of being coupled with the same focusing objective 26. The further patient adapters 28b to 28e will be described more precisely with reference to FIGS. 4b to 4e. Firstly, however, it will be demonstrated generally which influence differing patient adapters have on the optical effect of the laser device 10.

[0064] In FIGS. 2a to 2f six different types of patient adapter 28u, 28v, 28w, 28x, 28y, 28z are shown. Patient adapter 28u includes a contact lens 30u with an abutment face 32u for abutment against the eye 16 and enables a machining of the cornea 16a of the eye 16 with the aid of the laser beam 14. On the other hand, patient adapter 28v includes a contact lens 30v with an abutment face 32v for abutment against the eye 16 and enables a machining of the lens 16b of the eye 16 with unchanged setting of the laser device 10. Accordingly, with the same laser device 10 (and, for example, with identical setting of the same) a change of the optical effect of the laser device 10 can be obtained. Furthermore, patient adapter 28w enables a machining of the iris 16c of the eye 16 with the aid of the laser beam 14; patient adapter 28x enables a machining of the iridocorneal angle 16d of the eye 16 with the aid of the laser beam 14; patient adapter 28y enables a machining of the vitreous body 16e of the eye 16 with the aid of the laser beam 14; and patient adapter 28z enables a machining of the retina 16f of the eye 16 with the aid of the laser beam 14. Patient adapter 28w includes a contact lens 30w with an abutment face 32w for abutment against the eye 16; patient adapter 28x includes a contact lens 30x with an abutment face 32x for abutment against the eye 16; patient adapter 28y includes a contact lens 30y with an abutment face 32y for abutment against the eye 16; and patient adapter 28z includes a contact lens 30z with an abutment face 32z for abutment against the eye 16.

[0065] The optical effect of the laser device 10 in the case where use is made of patient adapter 28u is distinguished by the fact that the laser beam 14 is focussed in the cornea 16a. This means, inter alia, that the focal point of the laser beam 14 is situated in the cornea. For the machining of the cornea 16a, for a typical eye it is advantageous that the focus location z.sub.0 (i.e. the spacing of the focal point from the abutment face 32u of the patient adapter 28u for abutment of the eye 16 for a defined state of the z-scanner 22) may attain a value of about 110 μm. In addition, for the machining of the cornea usually a variable setting of the depth of focus of Δz=0 . . . 1200 μm is required—that is to say, a range of adjustment of the focal point of about 1.2 mm. Furthermore, normally a spot diameter of the focal point of around 3-5 μm and a scan-field diameter Φ.sub.F of around 12 mm are required. These properties are satisfied, for example, by patient adapter 28u.

[0066] If the settings of the laser device 10 are retained and only patient adapter 28u is replaced by patient adapter 28v, the focal point of the laser beam 14 does not lie in the cornea 16a, but in the lens 16b of the eye 16 (the mean focus location z.sub.0 assumes, for example, a value of 5 mm). This is obtained by virtue of a shorter length L.sub.2 of patient adapter 28v in comparison with the length L.sub.1 of patient adapter 28u. Furthermore, by virtue of patient adapter 28v it is ensured that, for example, a setting of the depth of focus of Δz=3 . . . 12 mm is possible, the spot diameter of the focal point amounts to 5 μm to 10 μm, and the scan-field diameter amounts to about 7 mm. As a result, a machining of the lens 16b of the eye is made possible despite the use of the same laser device 10.

[0067] The above remarks are applicable to the use of the further patient adapters 28w, 28x, 28y, 28z. Also when one of these patient adapters 28w, 28x, 28y, 28z is connected to the same laser device 10, a different treatment region is obtained, for example, through the possibility of a differing setting of the depth of focus and the existence of a differing spot diameter as well as a differing scan-field diameter. A summary of typical values of these is to be found at the end of this description.

[0068] The significance of the aforementioned parameters will be described further on the basis of FIG. 3.

[0069] In FIG. 3 the focus location z.sub.0 of the laser beam 14 may amount in exemplary manner to approximately 0.8 mm. The focus location z.sub.0 specifies how deeply the focal point is situated in the z-direction for a defined state of the z-scan in the eye (here with respect to the anterior surface of the crystalline lens 16b; with respect to abutment face 32y the focus location z.sub.0 amounts in exemplary manner to about 4 mm). The range of depth of focus Δz of the laser beam according to FIG. 3 amounts in exemplary manner to about 4 mm and specifies the range of adjustment of the focal point in the z-direction with one and the same laser device 10. The scan-field diameter Φ.sub.F of, in exemplary manner, about 8 mm specifies the diameter of the region that is capable of being irradiated in the x-y direction by the laser beam 14 (with one and the same laser device 10). As can be discerned from FIG. 3, for the machining of the cornea 16a a larger scan-field diameter Φ.sub.F is required than for the machining of the lens 16b. On the other hand, for the machining of the lens 16b higher values for the mean focus location z.sub.0 with respect to abutment face 32y and also a larger range of adjustment Δz are necessary than for the machining of the cornea. However, the values stated for these in exemplary manner are not to be understood as being restrictive but serve merely for illustration.

[0070] FIGS. 4a, 4b, 4c, 4d and 4e show various patient adapters 28a, 28b, 28c, 28d and 28e for use with the laser device 10. Depending on the patient adapter 28a, 28b, 28c, 28d and 28e being used, a differing optical effect in the laser device 10 can be brought about. Patient adapter 28a shown in FIG. 4a is suitable for implementing treatments of the cornea 16a of the eye 16, such as the implementation of incisions in the cornea 16a, by means of the laser device 10.

[0071] Patient adapter 28a is, as shown in FIG. 1, detachably coupled with the focusing objective 26 and constitutes an abutment interface for the cornea 16a of the eye 16. For this purpose, patient adapter 28a includes a contact element 30a that is transparent to the laser radiation and that on its underside facing towards the eye includes an abutment face 32a for the cornea 16a. Abutment face 32a is realised in the case of patient adapter 28a as a plane surface and serves for levelling the cornea 16a, by contact element 30a being pressed against the eye 16 with appropriate pressure or by the cornea 16a being aspirated onto abutment face 32a by underpressure. In the case of the plane-parallel design shown in FIG. 4a, contact element 30a is ordinarily designated as an applanation plate and is fitted to the narrower end of a conically widening carrier sleeve 34a. The connection between contact element 30a and the carrier sleeve 34a may be permanent, for example by virtue of adhesion bonding, or it may be detachable, for instance by virtue of a screw coupling. Alternatively, an integrally-produced injection-moulded part may find application. In a manner not represented in any detail, the carrier sleeve 34a has at its wider sleeve end, in the drawing the upper end, suitable coupling structures for coupling onto the focusing objective 26.

[0072] The laser beam 14, which is indicated schematically in FIG. 4a, penetrates the body of the patient adapter 28a, which is transmitting in respect of the laser radiation, and impinges on the planar contact lens 30a. Both faces (the abutment face 32a facing towards the eye 16 and the face 33a facing away from the eye) of the planar contact lens 30a are shaped flat. The eye 16 to be treated bears against the abutment face 32a of the contact lens 30a. After penetrating the contact lens 30a the laser beam 14 impinges on the cornea 16a at a focus indicated schematically. By x-y displacement and z-displacement of the focal point, incisions can now be implemented in the cornea 16a in accordance with the type of incision figure predetermined by the control program.

[0073] The reference symbols in FIGS. 4b to 4e corresponding to the reference symbols from FIG. 4a denote the corresponding elements.

[0074] FIG. 4b shows a patient adapter 28b that is suitable for carrying out treatments in the lens 16b of the eye 16 and capable of being coupled with the focusing objective 26. Just like patient adapter 28a from FIG. 4a, patient adapter 28b according to FIG. 4b includes a planar contact lens 30b. Patient adapter 28b includes a shorter length L.sub.2 than patient adapter 28a (with a length L.sub.1). That is to say, in comparison with patient adapter 28a according to FIG. 4a, which is suitable for the treatment of the cornea 16a, patient adapter 28b according to FIG. 4b, which is suitable for the treatment of the lens 16b, is shortened in the z-direction. As can be discerned in FIG. 4b, this shortening causes the focal point of the laser beam 14 to come to be situated not in the cornea 16a but in the lens 16b. With the aid of the x-y displacement and also the z-displacement of the focal point, incisions can now be generated in the lens 16b. If the laser beam 14 is deflected laterally, this being indicated on the basis of the further laser beam 14b in FIG. 4b, a laterally displaced focal point results in the lens 16b. As indicated schematically in FIG. 4b, the focal points have a differing focus diameter, depending upon their focus location in the x-y direction and in the z-direction. As can be discerned in FIG. 4b, the focus diameters increase in the lateral direction and in the axial direction, starting from the focal point of the central laser beam 14. This non-uniform focusing in the various depth regions and with lateral beam deflection can be compensated by an increase in the laser-pulse energy, in order to obtain the desired photodisruption threshold also in the marginal regions of the lens 16b. Alternatively, however, the non-uniform focusing may also be compensated by an adaptive optical element, a diffractive optical element or an element shaped with a freeform surface.

[0075] FIG. 4c shows a patient adapter 28c that is suitable for the treatment of the lens 16b and capable of being coupled with the focusing objective 26. Instead of the planar contact lens 30b used in patient adapter 28b according to FIG. 4b, in patient adapter 28c according to FIG. 4c use is made of a concavo-convex contact lens 30c. In the case of this concavo-convex contact lens 30c the face 33c facing away from the eye 16 is convexly shaped, whereas the abutment face 32c facing towards the eye 16 (the face bearing against the eye) is concavely shaped. By virtue of the concave shaping of the abutment face 32c facing towards the eye, the rise in intraocular pressure is lessened. The contact lens 30c is shaped in such a manner that the changes in the focus diameter arising in the case of patient adapter 28b from FIG. 4b are compensated at the focal points. As can be discerned in FIG. 4c, the central focal points (compared with FIG. 4b) are either retained (they remain unchanged) or slightly enlarged (worsened), whereas the focus diameters of the focal points in the marginal regions (compared with FIG. 4b) both in the lateral direction and in the axial direction are reduced (improved). Therefore the focus diameters of the focal point include an at least almost constant focus diameter, irrespective of the location of the focal point in the lateral and axial directions. The at least almost constant focus diameter may, for example, be obtained by virtue of freeform surfaces formed on the contact lens 30c. For example, the abutment face 32c facing towards the eye and/or the face 33c of the contact lens 30c facing away from the eye may have been shaped as a freeform surface. As a result, the energy of the laser radiation 14 that is necessary for photodisruption in the marginal regions does not have to be increased or increased so intensely as in the case where use is made of patient adapter 28b according to FIG. 4b but can be kept at least almost constant.

[0076] Patient adapter 28d in FIG. 4d differs from patient adapter 28c from FIG. 4c only by virtue of the fact that instead of the concavo-convex contact lens 30c use is made of a concavo-planar contact lens 30d. In the case of this concavo-planar contact lens 30d the abutment face 32d facing towards the eye 16 is concavely shaped and the face 33d facing away from the eye is planar. Instead of the concavo-planar contact lens 30d, use may also be made of a concavo-concave contact lens, wherein both the abutment face facing towards the eye 16 and the face facing away from the eye 16 are concavely shaped. The contact lens 32d may also include freeform surfaces on one or both of faces 32d, 33d. As can be discerned in FIG. 4d, patient adapter 28d also causes the focus diameters to be at least almost constant both in the lateral direction and in the axial direction.

[0077] Patient adapter 28e shown in FIG. 4e includes a planar contact lens 30e, wherein both the abutment face 32e (face 32e facing towards the eye) and the face 33e situated opposite the abutment face (face 33e facing away from the eye) are shaped in planar manner. In addition, in patient adapter 28e an optical ancillary element 35 is formed. The optical ancillary element includes a concave face 35a facing towards the eye and a planar face 35b facing away from the eye. One or both of faces 35a, 35b may have been shaped as freeform surfaces. As can be discerned in FIG. 4e, the optical ancillary element brings about a diminution of the focus diameters in the marginal regions. In the central regions an enlargement of the focus diameters and hence an adaptation of the focus diameters at all positions in the lens 16b can be brought about. In the central regions the focus diameter can also remain unchanged.

[0078] Patient adapter 28f shown in FIG. 4f includes a concavo-convex contact lens 30f, wherein the abutment face 32f (face 32f facing towards the eye) is concavely shaped and the face 33f situated opposite the abutment face (face 33f facing away from the eye) is convexly shaped. The contact lens 30f may also include optical freeform surfaces on one or on both of faces 32f, 33f. As can be discerned in FIG. 4f, patient adapter 28f also causes the focus diameters to be at least almost constant both in the lateral direction and in the axial direction. Patient adapter 28f from FIG. 4f corresponds to patient adapter 28x from FIG. 2d.

[0079] Irrespective of the element (optical ancillary element 35, contact lens 30c, contact lens 30d) on which one or more freeform surfaces have been formed, the at least one freeform surface may have been matched to an average human eye or may have been formed in patient-individual manner. So a patient adapter may include one or more freeform surfaces which in an average human eye bring(s) about the desired adaptation of the focus diameter. However, it is also conceivable to survey the eye prior to the machining of the human eye and to derive patient-individual data therefrom. From the patient-individual (eye-specific) data, freeform surfaces can be calculated which are then formed in the associated patient-individual patient adapters. As a result, the precision of the machining can be increased. It is similarly conceivable to add wavefront corrections by virtue of the adaptive system taking the form, in exemplary manner, of a mirror 42, in order to increase the precision of the machining.

[0080] Furthermore, each of the freeform surfaces may have been provided with an optical coating, in order to reduce reflection losses of the laser radiation 14.

[0081] As described in connection with the Figures, with the aid of the differing patient adapters 28a to 28e differing treatments can be carried out with the same laser device 10 even if the settings of the laser device remain unchanged. Consequently a system is made available with which differing types of treatment can be realised with one and the same laser device.

[0082] In conclusion a Table, to be regarded as exemplary, will be given which specifies values that are typical (but not to be understood as restrictive) for the purpose of treating a certain region of the eye.

TABLE-US-00001 Mean depth of focus z.sub.0 [mm] Range of Necessary starting from depth of focus size Lateral (x-y) Necessary Treatment corneal surface focus Δz ΦF scan range laser energy region z = 0 mm [mm] [μm] [mm] [μJ] Cornea 0.3 0.0 . . . 1.2 3 . . . 5 12 0.5 . . . 2.0  Lens 5.0  3.0 . . . 10.0 ≤10 7 2.0 . . . 10.0 Vitreous 15  7 . . . ~20 ≤10 ≥15 5 . . . 10 body Retina 23 20 . . . 28 ≤5 . . . 10  ≥15 <1 Iridocorneal 3 2 . . . 6  <10 ~5 10 angle